Review and outlook of solar energetic particle measurements on multispacecraft missions
The earliest evidence of spatial distributions of solar energetic particles (SEPs) compared events from many different source longitudes on the Sun, but the early Pioneers provided the first evidence of the large areas of equal SEP intensities across the magnetically confined “reservoirs” late in th...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-08-01
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| Series: | Frontiers in Astronomy and Space Sciences |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fspas.2023.1254266/full |
| _version_ | 1797730311506755584 |
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| author | Donald V. Reames |
| author_facet | Donald V. Reames |
| author_sort | Donald V. Reames |
| collection | DOAJ |
| description | The earliest evidence of spatial distributions of solar energetic particles (SEPs) compared events from many different source longitudes on the Sun, but the early Pioneers provided the first evidence of the large areas of equal SEP intensities across the magnetically confined “reservoirs” late in the events. More detailed measurements of the importance of self-generated waves and trapping structures around the shock waves that accelerate SEPs were obtained from the Helios mission plus IMP 8, especially during the year when the two Voyager spacecraft also happened by. The extent of the dozen widest SEP events in a solar cycle, which effectively wrap around the Sun, was revealed by the widely separated STEREO spacecraft with three-point intensities fit to Gaussians. Element abundances of the broadest SEP events favor average coronal element abundances with little evidence of heavy-element-enhanced “impulsive suprathermal” ions that often dominate the seed population of the shocks, even in extremely energetic local events. However, it is hard to define a distribution with two or three points. Advancing the physics of SEPs may require a return to the closer spacing of the Helios era with coverage mapped by a half-dozen spacecraft to help disentangle the distribution of the SEPs from the underlying structure of the magnetic field and the accelerating shock. |
| first_indexed | 2024-03-12T11:42:26Z |
| format | Article |
| id | doaj.art-474a46de36bd445186e0ad678aefbb9f |
| institution | Directory Open Access Journal |
| issn | 2296-987X |
| language | English |
| last_indexed | 2024-03-12T11:42:26Z |
| publishDate | 2023-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Astronomy and Space Sciences |
| spelling | doaj.art-474a46de36bd445186e0ad678aefbb9f2023-08-31T13:08:56ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2023-08-011010.3389/fspas.2023.12542661254266Review and outlook of solar energetic particle measurements on multispacecraft missionsDonald V. ReamesThe earliest evidence of spatial distributions of solar energetic particles (SEPs) compared events from many different source longitudes on the Sun, but the early Pioneers provided the first evidence of the large areas of equal SEP intensities across the magnetically confined “reservoirs” late in the events. More detailed measurements of the importance of self-generated waves and trapping structures around the shock waves that accelerate SEPs were obtained from the Helios mission plus IMP 8, especially during the year when the two Voyager spacecraft also happened by. The extent of the dozen widest SEP events in a solar cycle, which effectively wrap around the Sun, was revealed by the widely separated STEREO spacecraft with three-point intensities fit to Gaussians. Element abundances of the broadest SEP events favor average coronal element abundances with little evidence of heavy-element-enhanced “impulsive suprathermal” ions that often dominate the seed population of the shocks, even in extremely energetic local events. However, it is hard to define a distribution with two or three points. Advancing the physics of SEPs may require a return to the closer spacing of the Helios era with coverage mapped by a half-dozen spacecraft to help disentangle the distribution of the SEPs from the underlying structure of the magnetic field and the accelerating shock.https://www.frontiersin.org/articles/10.3389/fspas.2023.1254266/fullsolar energetic particlesshock wavescoronal mass ejectionssolar jetssolar system abundancesmultispacecraft missions |
| spellingShingle | Donald V. Reames Review and outlook of solar energetic particle measurements on multispacecraft missions Frontiers in Astronomy and Space Sciences solar energetic particles shock waves coronal mass ejections solar jets solar system abundances multispacecraft missions |
| title | Review and outlook of solar energetic particle measurements on multispacecraft missions |
| title_full | Review and outlook of solar energetic particle measurements on multispacecraft missions |
| title_fullStr | Review and outlook of solar energetic particle measurements on multispacecraft missions |
| title_full_unstemmed | Review and outlook of solar energetic particle measurements on multispacecraft missions |
| title_short | Review and outlook of solar energetic particle measurements on multispacecraft missions |
| title_sort | review and outlook of solar energetic particle measurements on multispacecraft missions |
| topic | solar energetic particles shock waves coronal mass ejections solar jets solar system abundances multispacecraft missions |
| url | https://www.frontiersin.org/articles/10.3389/fspas.2023.1254266/full |
| work_keys_str_mv | AT donaldvreames reviewandoutlookofsolarenergeticparticlemeasurementsonmultispacecraftmissions |